Abnormal or prodigious animals were regarded as signs or omens of impending evil. Extended by late 14c. to imaginary animals composed of parts of creatures (centaur, griffin, etc.). Meaning "animal of vast size" is from 1520s; sense of "person of inhuman cruelty or wickedness" is from 1550s. As an adjective, "of extraordinary size," from 1837. In Old English, the monster Grendel was an aglæca, a word related to aglæc "calamity, terror, distress, oppression."

The main point I got from that video is that monsters mostly exist, in mythology, because you can't have heroes unless you have monsters, for heroes to defeat. Fair enough.

I then thought about the old testament God, to think if Gods and monsters are sort of the same thing. Why didn't God have to defeat another monster to prove he was all powerful? Didn't God simply defeat humans who were the enemies of the Jewish tribes? When God caused the flood, to kill all humans, didn't that initially make him a monster?

I'm thinking that the old testament seems to contain a mix of Joseph Campbell's story lines for Gods, monsters and heroes, all mixed up together. I guess that's because that's what had to happen when the very early Jewish story tellers had make a single religious story from what were separate stories, that once did follow God, monster or hero story lines.

I found a review of Crash Course Mythology posted by someone else whose videos I've been watching, ReligionForBreakfast, who posts some very interesting videos on religions and their respective mytholoogy. He offers two things he liked about the series, and two things he disliked:

I agree with his Like #1 and his two dislikes, personally. His Like #2 was the opposite of my own feelings, in that I felt the Crash Course Mythology videos didn't have enough cross-cultural perspective.